Refrigeration



3 Sheets-Sheet 1 A. G. HELLSTROM REFRIGERATION June 15, 1965 Filed Dec. 4, 1963 IUHII INVENTOR.

B Mf flfZZi/VE/ June 15, 1965 A. G. HELLSTROM REFRIGERATION 3 Sheets-Sheet 2 Filed Dec. 4, 1963 INVENTOR. WM m wyf June 15, 1965 A. G. HELLSTROM REFRIGERATION 3 Sheets-Sheet 5 Filed Dec. 4, 1963 INVENTOR.

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MM MW B @M/% United States Patent Ofiice 3,188,831. Patented June 15, 1965 3,188,831 REFRIGERATION Axel Gosta Hellstrorn, .lohanneshov, Sweden, assignor to Aktieholaget Electroiux, Stockholm, Sweden, 21 corporation of Sweden Filed Dec. 4, 1963, Ser. No. 327,913 Claims priority, application Sweden, Dec. 4, 1962, 13,053/62 12 Claims. ((31. 62-288) My invention relates to refrigeration, and more particularly to cooling of the thermally insulated interior of a refrigerator.

It is an object of my invention to provide an improvement for cooling thermally segregated spaces of a refrigerator cabinet with a compression refrigerating system.

Another object of my invention is to cool thermally segregated spaces of a refrigerator with a cooling unit of a compression refrigerating system formed from a pair of' metal sheets in intimate physical contact with one another and having passage means therebetween, the metal sheets including a first cooling unit section of annular form disposed within a first space and thermally segre gated therefrom and a second cooling unit section comprising a plate-like member disposed alongside the first cooling unit section in thermal relation with the first space.

A further object of the invention is to employ a cooling unit of this kind formed from a pair of metal sheets to maintain thermally segregated spaces at temperatures respectively below and above the freezing temperature of water.

A still further object is to provide an improved refrigerator having one of the thermally insulated walls of the cabinet formed with an opening closed by a removable insulated wall part, the thermally insulated interior of the cabinet being cooled by a cooling unit therein forming part of a compression refrigerating system, and the cooling unit being connected to the removable wall part in such manner that the entire dead-weight load of the cooling unit is carried by the wall part and the cooling unit is mounted on the wall part in cantilever fashion with the cooling unit extending horizontally into the cabinet interior from the wall part.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawings, in which FIG. 1 is a fragmentary horizontal sectional view of a household refrigerator embodying my invention; FIG. 2 is a fragmentary vertical sectional view taken at line 2-2 of FIG. 1; FIG. 3 is a perspective view, partly broken away and in section, of parts shown in FIGS. 1 and 2; FIG. 4 is a side elevation of parts shown in FIGS. 1, 2 and 3; FIG. 5 diagrammatically illustrates a refrigeration system including a plan view of metallic sheeting with fluid passage means formed therebetween which I employ in forming parts shown in FIGS. 1 to 4; and FIG. 6 is a sectional view taken at line 6-6 of FIG. 5.

Referring to FIG. 1, I have shown my invention embodied in a household refrigerator comprising a cabinet 10 having an inner liner or shell 11 arranged within an outer shell 12 and insulated therefrom with any suitable insulating material 14. The inner shell 11 defines a thermally insulated storage space 15 having spaced lateral insulated side walls 16 and a rear insulated wall 17 and into which access may be had by a door (not shown) hinged at the front of the cabinet.

Adjacent to one of the lateral side walls 16 the rear wall 17 is formed with an opening 18 having a removable cover or closure member 19, as best shown in FIG. 1. The closure member 19 comprises a cup-shaped shell 20 having a bottom 20a forming part of the inner shell 11 and a lateral side wall 20b of rectangular shape extending rearward therefrom. The closure member 19 holds suitable insulation 21 and is provided with an outer plate 22 which is of greater cross-sectional area than the opening 18 and formed with spaced openings 22a to receive suitable fastening means 22b for removably mounting the closure member 19 in position at the rear of the cabinet 10.

A cooling unit or evaporator 23 of a compression refrigerating system is disposed in the upper part of the space 15. The cooling unit 23 includes a low temperature cooling unit section 23a defining a frozen food compartment 24 and a higher temperature cooling unit section 23!) employed for cooling the space 15. The low temperature cooling unit section 23a is arranged within an outer shell 25 and insulated therefrom with suitable insulating material 26. The higher temperature cooling unit section 23b is disposed outside the shell 25 and spaced therefrom for cooling air in storage space 15 which flows in intimate physical contact with both sides thereof to induce natural draft circulation of air in the space 15 to effect cooling thereof.

The cooling unit 23is provided with a front plate 27 formed with an access opening having a rearwardly extending flange 27a fixed at 27 b to the forward peripheral edge of the low temperature cooling unit section 23a, as shown in FIGS. 1 and 3. As shown in FIG. 1, the frozen food compartment 24 is provided with a cover 28 hinged at 29 to the front plate 27.

As shown in FIG. 5, the cooling unit 23 forms part of a compression refrigerating system which includes a motor-compressor unit 30 comprising a casing within which a motor and compressor are disposed. The motorcompressor unit 30 desirably is located at the rear of the cabinet exteriorly of the thermally insulated space. Compressed refrigerant gas discharged from the motor-compressor unit 30 flows through a connection 31 to a condenser 32 in the form of a looped coil having a plurality of heat dissipating elements fixed thereto for cooling the refrigerant by air circulating in thermal exchange relation therewith at the rear of the cabinet 10.

The refrigerant is condensed in the condenser 32 and flows therefrom to passage means 33 under the control of a small diameter flow-restricting or capillary tube 34. From passage means 33 refrigerant flows through passage means 35 to passage means 36 in the low temperature cooling unit section 23a. From the passage means 36 in the low temperature cooling unit section 23a refrigerant flows through passage means 37 to an accumulator 38 in the higher temperature cooling unit section 23b. Vaporized refrigerant flows from passage means 36 to the accumulator 38, and this vapor, together with vapor formed in the accumulator 38, is withdrawn from passage means 39 by the motor-compressor unit 30 through a suction line 40 which is in thermal exchange relation along its length with the flow-restricting tube 34. As shown in FIG. 5, the suction line 40 and flow-restricting tube 34 form a heat exchanger 41 with the tube 34 lengthwise of and within the suction line.

The cooling unit 23 is fabricated of sheet metal and comprises sheets of metal 42 and 43 which are united and held together in intimate physical contact with one another and provided with embossings. The embossings form a path of flow for the refrigerant which in cludes the passage means 33, 35,36, and 37, the accumulator 38, and the passage means 39. The metal sheets i by the low and higher temperature cooling unit sections 23a and 23b are integrally connected to'one another by a relatively narrow strip or connecting bridge which the passage means 35 and 37 are formed. 1

In accordance with my. invention, the metal sheets 4 and 43 are bent in such manner that one. portion thereofis of annular form and provides the low temperature cooling unit section 23a and another portion thereof is plate-like in. character and provides the higher temperature cooling unit section 2312 which is disposed along side the low temperature cooling unit section 23a. best shown in FIGURES land 5, the metal. sheets 42 and 43 are bent along the dotted lines 47, 48, and 49 to,

provide the four-sided low temperature cooling unit section 23a of annular form, the metal sheets haying spaced slots 50 adjacent to the notch 44 which receive tabs 51 extending outward from the ends'of the sheets. passing through the slots 50, the tabs 51 are bent to hold the. end edges of the sheets contiguous to an intermediate region of the sheets at the vicinity of the notch 4e, as best shown in FIG. 2. The metal'sheets are also bent substantially 90 at the vicinity of the connecting bridge or narrow strip 46 to provide the plate-like higher temperature cooling unit section 23b which is spaced from the low temperature cooling'unit section 23a and upright walls v vertically disposed alongside one of the thereof. a

As shown, in FIGS. 3 and 4, theflheat exchanger 41 extends through an opening in the outer plate 22of the rear cover or closure member 19 toward the front edge of the higher temperature cooling unit section 23b.'. The shell 20 of the rear closure member 19 is notched or cut away at 52 at the. region the heat exchanger 41 is disposed, the heat exchanger being spaced from the top'edge of and essentially in the same vertical plane as the higher temperature cooling unit section 23b.

The passage means 33 provided'in the higher temperature cooling unit section 23b is U-shaped and includes upright arms at thefront and rear thereof and a horizontal arm which extends across the bottom ofthe cooling unit section 23b and connects the lower ends of the upright arms. The upright arm of the passage means 33 at the front of the cooling unit section 23b includes a narrow constricted end portion 33a. The passage means 39 is L-shaped and includes a first part or upright arm 39a which extends vertically downward at 53 from the top edge of the cooling unit section 23b and merges with a After 7 V tinuous zig-zag path of flow for refrigerant from the rear to the front of the cooling unit section 2311. It will be noted that some of the longitudinal portions 36a are connected in parallel between the connecting portions 3622, as shown in FIG. 5. When FIG. 2 is compared with FIG. 5, the low temperature cooling unitlsection is longer in FIG. 5 than it is in FIG. 2. This is because parts of the metal-sheets 42 and 43 are broken away and the low temperature cooling unit section 23a is foreshortened in FIGJS.

' Unevaporated refrigerant passes from the passage means 36in the low temperature cooling unit section 23a through passage meansj37; in the'connecting bridge 46 into the accumulator '38. Refrigerant vapor passing into the accumulator38 from the pessagemeans36, together with refrigerant evaporating in the accumulator, is withdrawn therefrom into the suction line 40 of the heat exchanger41 through the passage means 39including the upright arm 39a thereof.

In conduct0rs'54 for supplying electrical energy from a source of supply 55 to the motor-compressor unit 36 is connected'a' switch 56, as shown in FIG. 5, which is ther- .mostati-cally controlled in any suitable manner respon- .sive to=a temperature condition affected by the higher temperature cooling unit section 23b. Such, a thermostatic control may include a thermal bulb 57 heat conductively connected to the higher temperature cooling higher temperature cooling unit section 23b.

During operation of the refrigerating system, the low and higher temperature cooling unit sections 2311 and 23b function to abstract heat from the frozen food compartment 24rand food storagespace 15, respectively. The portions of the coolingunit 23 having refrigerant passage means in open communication with one another will operate at substantially the same temperature range. When the metal sheets 42 and 43' areemployed to provide both the low and higher temperature cooling unit sections 23a and 235 which are integrally connected to one another by the relatively. narrow strip or connecting bridge 46, his possible nevertheless to maintain a substantial temperature differential between the frozen food compartment 24 and higher temperature food storage space 15 by correctly proportioning thelength of the path of flow of the refrigerant in the respective low and higher temperature cooling unit sections and the relacooling sections. When the refrigerating system is functioningto maintain the frozen food compartment 24 at second part or. narrow upper end portion 33a ofthe passage means 33. When the. heat exchanger 41 is connected to the cooling unit section 2311, the extreme end of the capillary tube 34 forming the inner passage thereof is inserted into the upper end of the constricted portion 33a of the passage means 33,and the extreme end of thesuc-- tionline 40 forming the outer passage thereof is positicned againstthe upper end of the upright arm 39a of the passage means 39. With the capillary tube 34 and suction line 40 in the positions just described they are simultaneously joined to the sheets 42and .43 at the regions thereof defining the constricted portion 33a and upright 'arm 39a, respectively, as by welding, for example; The

refrigerant passing into passage'means 33 from the flow: restricting tube 34 flows therefrom through passage means 35in the 'eonnectingbridge 4.6 into the passage,-

a-very low temperature'in a range of about l8 to 2 5 C., for example, the: higher temperature cooling unit section 23b will be fu'nctioningto maintain the storage space 15 at a temperature above freezing. Under these operating conditions, frost will. tend to form on the higher temperature cooling unit section 23b.

Q When defrosting of the higher temperature cooling unit section 23b is desired,'the thermostatic control will function to open switch 56,and disconnect the motorcompressorunit 30 from the source of electrical supply 55. The thermal bulb 57 is heat ,conductively connected to the higher temperature cooling unit section 23b at such a zone that, after the switch 56 is opened, the thermostatic control will not function to close switch 56 and connect the motor-compressor unit 30' to the source of electrical supply again until'the'higher temperature cooling unit section 23b is completely defrosted. By way of example, thethermostatic control may be of a type which can be arranged to always close the. switch 56 at substantially the same temperature, which may be about +1 or +2 C.,

for example, when the higher temperature cooling section 23b is completely defrosted; g V

7 Since the frozenfoo'd space 24 is effectively insulated by the insulating material 26 and the relatively narrow strip or connecting bridge 46 between the low and higher temperature cooling unit sections 23a and 23b provides a relatively poor heat conductive path therebetween, the temperature of the frozen food space 24 tends to remain at a substantially constant low temperature during the periods when the switch 56 is open and the motor-compressor unit 36 is disconnected from the source of electrical supply 55.

In accord with my invention, the rear of the cooling unit 23 is fixed to the cover or closure member 19 and carriedby the cover in cantilever fashion. As best shown in FIG. 1, the bottom 20a of the cup-shaped shell 20 defines a boss or protuberant part 26c extending forward from the rear insulated wall 11 of the cabinet 10. At the base of the protuberant part 200 the cup-shaped shell 26 is provided with an outwardly extending shoulder or flange 20d from the outer periphery of which the side walls 2% of the shell 20 extend rearward.

The protuberant part or boss 26c snugly receives the open rear end of the low temperature cooling unit section 23a which is fixed to the rim of the boss by suitable fastening means 59, such as screws, for example, the cooling unit section 23a in its fixed position bearing against the shoulder or flange 29d. If desired, reinforcing members (not shown) may be provided within the boss 200 which are adapted to be engaged by the fastening means 59 to reinforce the connection of the cooling unit section 2311 to the shell 20.

As best shown in FIGS. 1 and 3, the inner wall part 20a of the shell 20 is provided with two pairs of spaced tabs 60 disposed one above the other which receive the rear edge of the higher temperature cooling unit section 2312 to hold the latter in proper position on the cover or closure member 1?. Also, the inner wall part 20a is formed with a groove 61 which receives the rear edge of the outer shell 25 of the frozen food compartment 24.

The rear surface of the front plate 27 for the frozen food compartment is provided with a groove 62 which receives the front edge of the outer shell 25. The front plate 27 is also provided with rearwardly extending projections or tabs 63 which are disposed one above the other and notched at 63a to receive and hold the front edge of the higher temperature cooling unit section 23b, as best shown in FIGS. 1 and 4.

The rear of the front plate 27 is formed with a U-shaped projection 64 which receives the forward end of a U- shaped member 65 disposed beneath the higher temperature cooling unit section 23b. A member 66 defining a pocket 67 is fixed to the cover or closure member 19, as best shown in FIG. 3. The member 66 is notched at 68 to receive and hold the rear end of the U-shaped member 65. Frost melted on the higher temperature cooling unit section 23b collects in the U-shaped member 65 which functions as a drip trough in which water flows rearward into the pocket 67. As best shown in FIGS. 2 and 4, an inclined trough member 69 is fixed at 70 to the side of the outer shell 25 facing the higher temperature cooling unit section 23b. Water collected in the trough member 69 during defrosting periods flows rearward therein into the pocket 67. As best seen in FIGS. 1, 3 and 4, a conduit 71 extending through the cover or closure member 19 conducts water from the pocket 67 outside the cabinet where it is disposed of in any suitable manner.

In View of the foregoing, it will now be understood that the dead-weight load of both the cooling unit sections 2311 and 23b of the cooling unit 23 is transmitted directly to and carried by the rear cover or closure member 19. Further, the cooling unit 23 is carried in a cantilever fashion on the rear closure member 19 which also provides the rear insulated wall of the frozen food compartment 24.

When the rear edge of the cooling unit section 23a is fixed at 59 to the boss or protuberant part 20c of the cover 19, the rear edge of the cooling unit section 23b is positioned between the tabs 60 on the cover. Suitable insulating material formed of glass wool or rock wool may be placed about the cooling unit section 23a to provide the insulation 26 and the outer shell 25 is mounted over the insulation with its rear edge seated in the groove 61 formed in the inner wall 20:: of the cover 19. The front plate 27 can then be placed over the front of the cooling unit section 23a with the front edge of the outer shell 25 seated in the groove 62, the front edge of the cooling unit section 23b held in the notches 63a of the projections 63, and the U-shaped member positioned between the U-shaped projection 64 in the front plate 27 and the notch 68 in the member 66. With the aforementioned parts coacting with one another in the manner described, the front plate 27 is fixed at 27b to the front edge of the cooling unit section 23b. The rear part of the outer shell 25 of the frozen food compartment 24 is notched at 74, as shown in FIGS. 3 and 4. The narrow strip or connecting bridge 46 passes through the notch '74 and the insulation 26 and connects the top of the cooling unit section 23b and the cooling unit section 23a at the juncture of the top and the side wall thereof nearest to the cooling unit section 23b.

In order to provide a cooling unit 23 which is relatively light in weight, the metal sheets 42 and 43 of the cooling unit desirably are formed of aluminum or similar material. The shell 26 defining the inner wall 20a and lateral side walls 2% of the rear cover or closure member 19 may be formed of suitable plastic, such as polystyrene, for example. The outer shell 25 of the frozen food compartment 24 also may be formed of lightweight metal, such as aluminum or similar material. The front plate 27 of the frozen food compartment 24 may be formed of any suitable plastic or like material.

In order to reduce the dead-weight load carried by the removable cover or closure member 19 and provide an inexpensive construction, foamed plastic may be employed to insulate both the frozen food compartment 24 and the cover 19. In this event, the inner wall 20a of the shell 20 may be provided with openings 72 through which the foamable plastic can be introduced into the space between the outer shell 25 and the cooling unit section 2311, as best shown in FIG. 3. With the outer plate 22 of the cover 19 fixed to the lateral side walls 20a of the shell 20, suitable openings 73 also may be provided in the shell 20 for introducing foamable plastic in the cover 19, from which the foamed plastic will flow through the openings 72 into the space between the cooling unit section 2301 and the outer shell 25. The foamable plastic may be of a type like poly urethane and a substance like dichlorodifluoromethane. The resulting foamed plastic will completely fill the space between the cooling unit section 23a and the outer shell 25 and the interior of the cover 19 and adhere very strongly to the surfaces with which it comes in contact. After the foamed plastic has set and hardened, it is trimmed at the openings 73 which are then closed in any suitable manner. Foamed plastic insulation about the cooling unit section 23a and in the cover 19 mechanically reinforces the cover and the low temperature food compartment having the outer shell 25.

It will be understood that when the cover 19 is fixed in position to close the opening 18, suitable sealing material, such as that sold under the trademark Permagum, for example, may be employed about the periphery of the cover to seal the latter at the opening. By employing the metal sheets 42 and 43 to form the low and higher temperature cooling unit sections 2311 and 2312 which are integrally joined to one another, a cooling unit construction is provided that is easy to handle and which can be inserted without difiiculty through the opening 18 into the interior of the cabinet 10.

Modifications of my invention which has been described will occur to those skilled in the art. Therefore, as I desire my invention not to be limited to the particular ar- 7 rangement setforth,'I intend'in the claims to cover all those modifications which do not depart from the spirit and scope of the invention. e 1

I claim: 7 1. A refrigerator comprising space defined by thermally insulated walls includinga rear wall and spaced lateral side walls, a compression refrigerating system including a cooling unit disposed in 'said space which is formed from .a pair of metal sheets in'intimate physical contact with one another and having passage means therebetween, said' metal sheets including a first cooling unit section of annular form having spaced vertically extending side walls and top and bottom connecting walls and a'secondcooling unit section comprising a plate-like member vertically disposed alongside said first cooling unit section and a relatively narrow connecting strip therebetween, said strip providing a relatively poor heat conductive path between said first and second a cabinet having a storage 7 7 said flow-restricting tube and o cabinet havin a thermally'insulatcdinterior defined by- "thermally insulated walls, of a compression refrigerating cooling unit sections, said passage meansbetWeen-said sheets providing a path of flow forrefrige'rant having portions in said first and second cooling unit sections and said connecting strip and in which refrigerant flows' serially therethrongh, structure including saidfirst coolingxunit section of annular form providing a frozen'food compart ment from which said first cooling unit sectionis arranged to abstract heat, said last-mentioned structure comprising an outer shell disposed about the first cooling unit section in spaced relation therewith and insulation therebetween, said first and second cooling unit sections extending forward from said rear Walland saidconn'ecting strip being nearer to said rear Wall than to the front portions of said first and second cooling unitsections,'and said outer shell being notched to receive said connecting strip. V

2. A refrigerator comprising a cabinet having aflstorage space defined by thermally insulated walls, a compression refrigerating system includinga cooling unit disposed in' saidsuction line to said platelike member to effect communication of said tube with the second part'of said passage means and to effect communication of said suction line with the first part of said i passage means.

3. The combination with a refrigeratoreomprising a system including a cooling unit for effecting cooiing of the thermally; insulated interior, said cooling unitebeing formed from a pair of metal sheets in intimate physical contactwith oneanother and having passage means therebetwcen providing a path of flow for refrigerant having an inlet and'outlet at a zone of said contacting metal sheets, the outlet being defined by a first part of said passage rncans oextending inward from the periphery of said'contacting metal sheets at said zone, the inlet being defined by, asecond part of said passage means of smaller cross' ectional area than the outlet and cornmunicating With the first part of said passage means at a region of said zone removed from the periphery of said contacting metal sheets,'-the path of flow of crefrigerant in said coolsaid space which is formed from a pair of metal sheets in a V intimate physical contact with'one another and having passage means therebetween, said metal sheets includinga first cooling unit section of annular form and a second cooling unit section comprising 'a plate-like member disposed alongside said first' section and a relatively narrow connecting strip therebetween, said strip providing a relatively poor heat conductive path betweensaid. first and second cooling unit sections, said passage meansbetween said sheets providing a path of flow for refrigerant having portions in said first and second cooling unit sections and said connecting strip and in which refrigerant flows serially therethrough, structure including said first'co'oling unit section of annular form providing a frozen food compartment from which said first cooling unit section is arranged to abstract heat, means including said second cooling unit section for abstracting heat from said space, the path of flow of refrigerant formed by said passage means having an inlet and an outlet at a zone of said plate-like member, the out-let being defined by a first part of said passage means extending inward from the periphery of said platelike member at said zone, the inlet being defined by 'a second part ofsaid passage'means of smaller cross-sectional area than the outlet and communicating with the first part of said passage means at a region of said zone removed from the peripheryof said plate-like member, the path'of flow of refrigerantin said first and second cooling unit sections forming part of a circuit for circulation of refrigerant which includes a flow-restricting tube coming unit forming part of a circuit for circulation of refrigerant which includes a fiow restricting tube communicat ing with the inlet for conducting refrigerant thereto and a suction line communicating with the outlet for withdrawing refrigerant therefrom, at least a part of said tube being disposed ithin and extending lengthwise of said suction line, said tube projecting beyond the end of said suction line and extending through the first part of said passage means and terminating at the second part of said passage mean stin communication therewith, said suctionline communicating with said outlet at the periphery of said contacting metal sheets, and means for uniting said flow-restricting tube and said suction line .to said contacting metal sheets toetlect communication of said cooling unit section comprising a plate-like member disposed vertically alongside said first section and a relatively narrowconnecting strip" therebe'tween, said first and'second cooling unit sections and narrow connecting strip therebetween being integrallyconnected to one another by sa d contacting metal 'sheetsysaid strip providing a relatively poor heat conductive path between said first and second cooling unit sections, said passage means cooling unit section of annular form and insulation enveloping said first cooling unit section'defining an insulated frozen food compartment from which said first cooling unit section is arranged 'to abstract'heat, said plate-like member being spacedfrom thelast-rnentioned structure for cooling air flowing in intimate physical contact with both'sides thereof to induce natural draft circulation of air in said space-.to. effect coolingthereofi'and said connecting strip integrally connected to said first and second cooling unit sections extending through said insulation enveloping said first cooling unit section.

5. A refrigerator as set' forth in claim 4 in which said thermally insulated Walls include a rear wall and spaced lateral Walls defining the'space and said first cooling unit section of annular form includes spaced vertically extending side walls-and topland bottom connecting walls, said first and second cooling unit sections extendingforward from said rear wall and said connecting strip being at the vicinity of the rear wall of said space and extending through the insulation of the frozen food compartment between the top of said plate-like member and the juncture of the top and the side wall of said first cooling unit section nearest to said plate-like member.

6. A refrigerator as set forth in claim in which said rear wall is formed with an opening, a thermally insulated closure member for the opening, said first cooling unit section of annular form being open at the rear, and said insulated closure member overlying the rear opening of said first cooling unit section and in good physical contact therewith, whereby said rear insulated closure member cooperates with said enveloping insulation to provide said insulated frozen food compartment.

7. A refrigerating system as set forth in claim 4 in which said first and second cooling unit sections form part of a circuit for circulation of refrigerant which also includes a refrigerant translating device, and control means including a thermal element responsive to a temperature condition affected by said second cooling unit section for controlling said refrigerant translating device, the passage means in said first and second cooling unit sections being in open communication with one another and operable at substantially the same temperature range, the ratio of the length of the passage means in said first cooling unit section to the length of the passage means in said second cooling unit section and the ratio of the size of the part of the contacting metal sheets defining said first cooling unit section to the part of the contacting a said translating device operable only when defrosting of said second cooling unit section is substantially completed.

8. A refrigerator as set forth in claim 4 in which said thermally insulated walls defining said space comprise a plurality of vertical walls including a rear wall and spaced lateral side walls, said first and second cooling unit sections extending forward from said rear wall, said first cooling unit section of annular form being open at the rear, and means for mounting said first cooling unit section on said rear wall, whereby said rear wall closes the opening at the rear of said first cooling unit section and forms a part of the enveloping insulation therefor and carries the entire dead-weight load of said cooling unit and the latter is mounted on said rear wall in cantilever fashion with said cooling unit extending horizontally forward from said rear wall.

9. A refrigerator as set forth in claim 8 in which said rear wall is formed with an opening through which said cooling unit is insertable and removable into and from said space, and a removable thermally insulated closure member for closing said last-mentioned opening, said closure member having a protuberant part extending forward therefrom, and said mounting means mounting said cooling unit on said closure member with said protuberant part thereof nested in the rear opening of said first cooling unit section to provide a sleeve connection therebetween.

10. A refrigerator comprising a cabinet having an interior defined by thermally insulated walls including a rear wall and spaced lateral side walls, the rear wall having an opening, a removable insulated wall part for closing the rear opening, a compression refrigerating system including a cooling unit which is formed from a pair of metal sheets in intimate physical contact with one another and having passage means therebetween for flow of refrigerant, said metal sheets including a first cooling unit section of annular form open at both ends and a second cooling unit section comprising a plate-like member disposed alongside said first cooling unit section, means connecting one open end of said first cooling unit section and said insulated wall part to provide a unitary structure, said rear wall part serving to insulate said first cooling unit section at the one end thereof, said connecting means being so constructed and arranged that the entire dead-weight load of said cooling unit is carried by said wall part and said cooling unit is mounted on said wall part in cantilever fashion with said first and second cooling unit sections extending forward into the cabinet interior from said rear wall part, a front plate for said first cooling unit section, said plate having an opening communicating with the other open end of said first cooling unit section, means for fixing said plate to said first cooling unit section at the vicinity of the other open end thereof, a shell disposed about said first cooling unit section and spaced therefrom, insulation disposed between said shell and first cooling unit section, and means including said plate for anchoring said shell between said plate and said removable wall part.

11. A refrigerator comprising a cabinet having an interior defined by thermally insulated walls including a rear wall and spaced lateral side walls, the rear wall having an opening, a removable insulated wall part for closing the opening, a compression refrigerating system including a cooling unit which is formed from a pair of metal sheets in intimate physical contact with one another and having passage means therebetween for flow of refrigerant, said metal sheets including a first cooling unit section of annular form open at both ends and a second cooling unit section comprising a plate-like member disposed alongside said first cooling unit section, means connecting one open end of said first cooling unit section and said insulated wall part to provide a unitary structure, said rear wall part serving to insulate said first cooling unit section at the one end thereof, said connecting means being so constructed and arranged that the entire deadweight load of said cooling unit is carried by said Wall part and said cooling unit is mounted on said wall part in cantilever fashion with said first and second cooling unit sections extending forward into the cabinet interior from said rear wall part, a front plate for said first cooling unit section, said plate having an opening communicating with the other open end of said first cooling unit section, means for fixing said plate to said first cooling unit section at the vicinity of the other open end thereof, and means including said rear wall part and said front plate for anchoring said plate-like member therebetween.

12. A refrigerator as set forth in claim 11 including trough means disposed beneath said plate-like member for collecting water dripping from said member when defrosting is being effected, and means including said front plate for holding said trough means in position lengthwise of said plate-like member between said-rear wall part and said plate.

References (Iited by the Examiner UNITED STATES PATENTS 1,926,341 9/33 Lipman 62-449 X 2,065,536 12/36 Philipp 62-517 X 2,246,551 6/41 Stickel 62-5 13 X 2,713,776 7/55 Smith 62-5l7 X 2,774,221 12/56 Heidorn 62-441 X 2,776,549 l/57 Gerhardt 62519 ROBERT A. OLEARY, Primary Examiner. 

1. A REFRIGERATOR COMPRISING A CABINET AHVING A STORAGE SPACE DEFINED BYU THERMALLY INSULATED WALLS INCLUDING A REAR WALL AND SPACED LATERAL SIDE WALLS, A COMPRESSION REFRIGERATING SYSTEM INCLUDING A COOLING UNIT DISPOSED IN SAID SPACE WHICH IS FORMED FROM A PAIR OF METAL SHEETS IN INTIMATE PHYSICAL CONTACT WITH ONE ANOTHER AND HAVING PASSAGE MEANS THEREBETWEEN, SAID METAL SHEETS INCLUDING A FIRST COOLING UNIT SUCTION OF ANNULAR FORM HAVING SPACED VERTICALLY EXTENDING SIDE WALLS AND TOP AND BOTTOM CONNECTING WALLS AND A SECOND COOLING UNIT SECTION COMPRISING A PLATE-LIKE MEMBER VERTICALLY DISPOSED ALONGSIDE SAID FIRST COOLING UNIT SECTION AND A RELATIVELY NARROW CONNECTING STRIP THEREBETWEEN, SAID STRIP PROVDING A RELATIVELY POOR HEAT CONDUCTIVE PATH BETWEEN SAID FIRST AND SECOND COOLING UNIT SECTIONS, SAID PASSAGE MEANS BETWEEN SAID SHEETS PROVIDING A PATH OF FLOW FOR REFRIGERANT HAVING PORTIONS IN SAID FIRST AND SECOND COOLING UNIT SECTIONS AND SAID CONNECTING STRIP AND IN WHICH REFRIGERANT FLOWS SERIALLY THERETHROUGH, STRUCTURE INCLUDING SAID FIRST COOLING UNIT SECTION OF ANNULAR FORM PROVIDING A FROZEN FOOD COMPARTMENT FROM WHICH SAID FIRST COOLING UNIT SECTION IS ARRANGED TO ABSTRACT HEAD, SAID LAST-MENTIONED STRUCTURE COMPRISING AN OUTER SHELL DISPOSED ABOUT THE FIRST COOLING UNIT SECTION IN SPACED RELATION THEREWITH AND INSULATION THEREBETWEEN, SAID FIRST AND SECOND COOLING UNIT SECTIONS EXTENDING FORWARD FROM SAID REAR WALL AND SAID CONNECTING STRIP BEING NEARER TO SAID REAR WALL THAN TO THE FRONT PORTIONS OF SAID FIRST AND SECOND COOLING UNIT SECTIONS, AND SAID OUTER SHELL BEING NOTCHED TO RECEIVE SAID CONNECTING STRIP. 